Domestic Microwave Oven Magnetron Simulation To Improve The Emi Problems

Magnetron has broad applications in radar, communication, accelerating power, medical devices, home microwave oven and industrial heating for its small size, high efficiency and low cost. The manufacture technique and craftwork of magnetron have become more and more mature after being improved those years. However, there are still some problems needed to be investigated, such as the mechanism of mutual action between electrons and waves and the mode competition and selection during the action. At the same time, with the rapid development of the telecommunication, it is significant to attach more importance to the problem of Electro Magnetic Interference (EMI) for limited frequency spectrum. Furthermore, there are great challenges for magnetron trade with the rapid rising of price for raw materials. Therefore, it is crucial to develop the quality of the output frequency and lower the production cost.In this thesis, the main researching contents are listed as follows:1. The basic structures, work principle and technique index of magnetron are introduced, and the design methods are also given in theory.2. The characteristics of the cold cavity are studied by simulation, which are confirmed by experiment tests. The resonant frequencies for each mode are calculated, vector graphs of high frequency field for theπmode and other adjacent modes are devised, the influence on the mode division by no, single and double interlink are analyzed, respectively. The loaded quality factor are calculated and measured and the effect on the performance of magnetron for which are also studied shortly.3. The characteristic of the hot cavity are discussed using particle simulation. The results of output power and efficiency are in agreement with experiments. The influence on the rise and shake time, mode competition, output frequency and stability by cathode current are researched.4. The principle of depressing the high order harmonious waves by output parts of the magnetron is theoretically investigated. The output parts are optimized to improve the EMI problem and promote the production ratio by High Frequency Structure Simulator (HFSS) and Computer Simulation Technology (CST) software. 5. A new type of anode resonant system is designed, which can reach the purpose of saving cost and improving product capability through testing of every index.